Advanced testing of PV plants using portable SCADA tool

The Performance ratio (PR) describes the technical quality of PV installation. On yearly basis, it is a good performance indicator for monitoring and comparisons of PV plants at different locations, but for shorter testing periods or commissioning, weekly -based or hourly-based indicators are preferable. We have developed a testing tool based on small SCADA which allows on-field measurements. The main advantages are flexibility and speed of testing. Thanks to the recent developments of "smart" sensors, the measuring tool can be adapted and reconfigured in accordance with the scale and type of equipment under test. Sensor data are collected and processed on site and performance indicators are extracted nearly in real-time. This report describes the methodology and practical experience in two application cases implemented in the frame of PV CROPS project

A methodology for designing electrification programs for remote areas

One of the UN Sustainable Development Goals is the supply of sustainable energy even where no electrical grid is available. The photovoltaic rural electrification programs are the most common systems implemented in remote areas, especially in developing countries. These programs include the systems installation and their maintenance for a given period. Installation costs and even spare parts costs over time are usually well estimated. However, design and cost estimation of the maintenance systems is a difficult task, whose wrong management has often resulted in the failure of these electrification programs. In this work, a methodology for designing maintenance systemsand estimating costs is presented. The methodology includes a mixed integer linear programming model and a rule based expert system. The mathematical programming model allows obtaining the optimal size and accurate cost estimation of a maintenance system, based on precise information about the installed systems. This model is calibrated and validated with real running programs and will be used to get an enlarged data set of simulated cases if needed. The rule based expert system is obtained from the data set applying classification and regression methods with general information about the region and program to be run. It can be used for designing programs or for companies making decisions about being involved in a program to be developed. The methodology has been applied to real Morocco programs

Energía solar sostenible para el desarrollo rural y estimación de sus costes

Este trabajo presenta una metodología para la estimación de costes en programas de electrificación rural descentralizada basado en la instalación y mantenimiento de sistemas solares domésticos. La metodología presentada consta de dos fases: (1) modelo de optimización para estimación de costes y configuración de la estructura local (agencias, vehículos y personal) y (2) modelos estadísticos de clasificación y regresión lineal para la estimación de costes sujeto a características conocidas de antemano en un programa de esta envergadura. Esta metodología ha sido validada en un programa implantado en Marruecos donde la empresa encargada de la instalación, gestión y operación subestimó, principalmente, los costes de operación, provocando el incumplimiento de las condiciones del programa

Effect of SGLT2 inhibitors on stroke and atrial fibrillation in diabetic kidney disease: Results from the CREDENCE trial and meta-analysis

BACKGROUND AND PURPOSE: Chronic kidney disease with reduced estimated glomerular filtration rate or elevated albuminuria increases risk for ischemic and hemorrhagic stroke. This study assessed the effects of sodium glucose cotransporter 2 inhibitors (SGLT2i) on stroke and atrial fibrillation/flutter (AF/AFL) from CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation) and a meta-Analysis of large cardiovascular outcome trials (CVOTs) of SGLT2i in type 2 diabetes mellitus. METHODS: CREDENCE randomized 4401 participants with type 2 diabetes mellitus and chronic kidney disease to canagliflozin or placebo. Post hoc, we estimated effects on fatal or nonfatal stroke, stroke subtypes, and intermediate markers of stroke risk including AF/AFL. Stroke and AF/AFL data from 3 other completed large CVOTs and CREDENCE were pooled using random-effects meta-Analysis. RESULTS: In CREDENCE, 142 participants experienced a stroke during follow-up (10.9/1000 patient-years with canagliflozin, 14.2/1000 patient-years with placebo; hazard ratio [HR], 0.77 [95% CI, 0.55-1.08]). Effects by stroke subtypes were: ischemic (HR, 0.88 [95% CI, 0.61-1.28]; n=111), hemorrhagic (HR, 0.50 [95% CI, 0.19-1.32]; n=18), and undetermined (HR, 0.54 [95% CI, 0.20-1.46]; n=17). There was no clear effect on AF/AFL (HR, 0.76 [95% CI, 0.53-1.10]; n=115). The overall effects in the 4 CVOTs combined were: Total stroke (HRpooled, 0.96 [95% CI, 0.82-1.12]), ischemic stroke (HRpooled, 1.01 [95% CI, 0.89-1.14]), hemorrhagic stroke (HRpooled, 0.50 [95% CI, 0.30-0.83]), undetermined stroke (HRpooled, 0.86 [95% CI, 0.49-1.51]), and AF/AFL (HRpooled, 0.81 [95% CI, 0.71-0.93]). There was evidence that SGLT2i effects on total stroke varied by baseline estimated glomerular filtration rate (P=0.01), with protection in the lowest estimated glomerular filtration rate (45 mL/min/1.73 m2]) subgroup (HRpooled, 0.50 [95% CI, 0.31-0.79]). CONCLUSIONS: Although we found no clear effect of SGLT2i on total stroke in CREDENCE or across trials combined, there was some evidence of benefit in preventing hemorrhagic stroke and AF/AFL, as well as total stroke for those with lowest estimated glomerular filtration rate. Future research should focus on confirming these data and exploring potential mechanisms

Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to 300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m 2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to &lt;90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], &gt;300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of &lt;15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P&lt;0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P&lt;0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Seasonal changes in facilitation between an ascidian and a kelp in Patagonia

Positive interactions between species may change in outcome over time and may differ for the two interacting species. We explored the seasonal patterns of facilitation between an ascidian (Styela clava) and a macroalga (Undaria pinnatifida) by following their association for a complete sporophytic phase. In addition, we investigated how therelationship affected the morphometric parameters of U. pinnatifida, and whether the association had a negative outcome for S. clava. We performed monthly surveys in San Antonio Bay (Argentina) for nearly 1 yr to evaluate U. pinnatifida density (both the total and mature individuals exclusively) on different substrates to determine whether U. pinnatifida was more closely associated with S. clava than with inert substrates (i.e. consolidated andnonconsolidated). Moreover, we compared the morphometry of U. pinnatifida between substrates (S. clava vs. rock) andcollected S. clava individuals overgrown by U. pinnatifida and classified them by their holdfast coverage toassess their condition (dead or alive). A higher total density of U. pinnatifida was associated with S. clava than with other substrates from autumn to spring. U. pinnatifida individuals growing on S. clava were smaller than those growing on rock. Finally, the probability of S. clava dying increased for individuals with higher holdfast coverage, although the scarcity of dead individuals found suggested a negligible influence. Our findings indicate that whereas U. pinnatifida clearly benefitted from this interaction by appearing earlier in the field and presenting higherdensities that could benefit the population when associated with S. clava, for S. clava the relationship appeared more neutral.</p

Análisis demográfico de tres poblaciones de Zidona dufresnei localizadas en el Atlántico sudoccidental

El estudio de los patrones demográficos en especies que soportan una presión pesquera es fundamental para la conservación y manejo de sus poblaciones. Zidona dufresnei es un caracol marino endémico del Atlántico sudoccidental, y es una de las principales especies capturadas por la pesca artesanal. Además se caracteriza por las marcadas diferencias entre sus poblaciones respecto a la talla máxima alcanzada. El objetivo de este estudio fue evaluar la estructura poblacional y los patrones morfogravimétricos intra- e interpoblacionales en tres localidades distribuidas a lo largo del Mar Argentino (Mar del Plata, Golfo San Matías, Bahía San Antonio). El rango de tallas varió entre 80 y 230 mm. Los ejemplares más pequeños correspondieron a la Bahía de San Antonio, mientras que los más grandes al Golfo San Matías. En todos los casos, las distribuciones de frecuencias de tallas y pesos siguieron una distribución unimodal. No se encontraron diferencias significativas en los pesos y tallas entre sexos. El ancho, largo y peso total de los ejemplares difirieron significativamente entre los tres sitios tanto en la prueba global como en las comparaciones a posteriori. La proporción de sexos no difirió de 1:1. Los resultados obtenidos en este estudio ampliaron el rango de distribución batimétrica de Z. dufresnei, estableciendo su variación entre 0 y 120 m. Además, se registró una nueva talla máxima de 230 mm para esta especie en el Mar Argentino. Las diferencias entre las tres poblaciones estudiadas se deberían a las presiones ambientales locales o a un flujo génico interrumpido o reducido